Biology: Chapter 9: The Digestive System

Question 1

What is intracellular digestion

Answer 1

involves the oxidation of glucose and fatty acids to make energy

Question 2

What is extracellular digestion

Answer 2

occurs in the lumen of the alimentary canal

Question 3

What is mechanical digestion

Answer 3

physical breakdown of large food particles into smaller food particles

Question 4

what is chemical digestion

Answer 4

enzymatic cleavage of chemical bonds such as the peptide bonds of proteins or the glycosidic bonds of starches

Question 5

what is the pathway of the digestive tract

Answer 5

oral cavity -> pharynx -> esophagus -> stomach -> small intestine -> large intestine -> rectum

Question 6

what are the accessory organs of the digestive system

Answer 6

salivary glands, pancreas, liver, and gall bladder

Question 7

what is the enteric nervous system

Answer 7

in the wall of the alimentary canal and controls peristalsis; activity is upregulated by parasympathetic NS and downregulated by sympathetic NS

Question 8

which hormones promote thrist

Answer 8

ADH and Aldosterone

Question 9

which hormones promote satiety

Answer 9

Leptin and Cholecystokinin

Question 10

which hormones promotes hunger

Answer 10

glucagon and Ghrelin

Question 11

What is the first step in digestion

Answer 11

mastication (mechanical)/salivary amylase + lipase (chemical) forms a bolus which is swallowed

Question 12

what is the esophagus

Answer 12

propels food to the stomach using peristalsis and enters the stomach through the lower esophageal sphincter

Question 13

what are the four parts of the stomach

Answer 13

fundus, body, antrum, and pylorus

Question 14

what are the mucus cells of the stomach

Answer 14

produce bicarbonate rich mucus to protect stomach lining

Question 15

what are the chief cells of the stomach

Answer 15

secrete pepsinogen, a protease activated by the acidic environment of the stomach

Question 16

what are the parietal cells of the stomach

Answer 16

secrete HCl and intrinsic factor which is used for B12 absorption

Question 17

what are G cells of the stomach

Answer 17

secrete gastrin, a peptide hormone that increases HCl secretion and gastric motility

Question 18

What is the second step of digestion

Answer 18

Further mechanical and chemical digestion in the stomach which produces chyme; passes into the duodenum through the pyloric sphincter

Question 19

what is the duodenum

Answer 19

first part of the small intestine + chemical ingestion

Question 20

what is Disaccharidases in the duodenum

Answer 20

brush border enzymes that break down maltose, isomaltose, lactose, and sucrose into monosaccarides

Question 21

what are peptidases in the duodenum

Answer 21

aminopeptidase and dipeptidase

Question 22

what is enteropeptidase in duodenum

Answer 22

activates trypsinogen and procarboxypeptidases initializing an activation cascade

Question 23

what is secretin in duodenum

Answer 23

stimulates the release of pancreatic juices into the digestive tract and slows motility

Question 24

what is cholecytokinin in the duodenum

Answer 24

stimulate bile release from the gall bladder, release of pancreatic juices, and satiety

Question 25

How is the pancreas related to the digestive system

Answer 25

acinar cells produce pancreatic juices that contain bicarbonate, pancreatic amylase, pancreatic peptidases, and pancreatic lipase

Question 26

how is the liver related to the digestive system

Answer 26

synthesizes bile which can be stored in the gall bladder or secreted into the duodenum directly; processes nutrients, produces urea, detoxication, activation/inactivation of medication, synthesizes albumin and clotting factors

Question 27

what is the function of bile

Answer 27

bile emulsifies fats making them soluble and increasing their surface area

Question 28

what is bile made of

Answer 28

biles salts, pigments, and cholesterol

Question 29

what is the function of the gall bladder

Answer 29

stores and concentrates bile

Question 30

what is the jejunum and ileum

Answer 30

part of small intestine are primarily involved in absorption

Question 31

how is surface area in the small intestine increased

Answer 31

lined with villi which are covered with microvilli

Question 32

How is absorption conducted in the small intestine

Answer 32

1) water soluble compounds (monosaccarides, amino acids, small fatty acids, water) enter capillary bed 2) fat soluble compounds (fats, cholesterol, and fat soluble vitamins) enter the lacteal *lacteal is a vessel of the lymphatic system

Question 33

what is the function of the large intestine

Answer 33

absorbs water and salts forming semisolid feces

Question 34

what is the cecum

Answer 34

outpocketing of large intestine that accepts fluid from the small intestine through the ileocecal valve and is the site of attachment of the appendix

Question 35

what is the colon

Answer 35

divided into ascending, transverse, descending, and sigmoid portions

Question 36

what is the rectum

Answer 36

stores feces which is excreted through the anus